At present this page is just a repository for links to (slides for) talks I have given, and (drafts of) papers I have written, about the stack semantics. Comments and questions are also welcomed below.
Unbounded quantifiers and strong axioms in topos theory (talk at Novemberfest ‘09). This is an introduction intended for category theorists who may not be very familiar with categorical logic.
Unbounded quantifiers via 2-categorical logic (talk at the ASL Annual Meeting in March ‘10). This talk assumes some background with 1-categorical logic, and goes on to make the connection with 2-categorical logic.